87185-17-9Relevant academic research and scientific papers
Intramolecular and intermolecular Diels-Alder reactions of acylhydrazones derived from methacrolein and ethylacrolein
Allcock,Gilchrist,Shuttleworth,King
, p. 10053 - 10064 (2007/10/02)
The intramolecular Diels-Alder reactions of hydrazones derived from methacrolein or ethylacrolein and terminally unsaturated N-acyl-N-methylhydrazines have been investigated. The hydrazones 7b and 7c derived from N-methyl-N-pent-4-enoylhydrazine 3b were found to undergo intramolecular [4 + 2] cycloaddition above 140°C and the pyridopyridazones 12 were isolated. The corresponding hydrazones 8b and 8c from N-methyl N-pent-4-ynoylhydrazone 4a reacted similarly and gave as the final products the pyridines 13. The scope of the reaction is limited, as was shown by the failure of several other terminally unsaturated hydrazones of αβ-unsaturated aldehydes to undergo intramolecular cycloaddition. These hydrazones did, however, undergo intermolecular [4 + 2] cycloaddition to N-phenylmaleimide. Other hydrazones 15 of methacrolein, including the benzoylhydrazone and the phenylhydrazone, also reacted with N-phenylmaleimide to give the pyridine 14b by way of an isolable dihydropyridine 16.
Mild Generation of Alkylidenecarbenes from (Tosylazo)alkenes and Silylvinyl Triflates. Mode of Decomposition and Nature of the Carbene Intermediates
Fox, Dennis P.,Bjork, Jon A.,Stang, Peter J.
, p. 3994 - 4002 (2007/10/02)
(Tosylazo)alkenes, R2C=CHN=NTs, decomposed in olefin-solvent mixtures both under neutral conditions at room temperature and with amine bases present to produce alkylidenecyclopropanes in moderate to good yields.Diazoalkenes, R2C=C=N2, were implicated as t
